Tag-only ecosystem mode + generic file updaters (GitHub Actions, Terraform, C/C++ presets)

[goosewobbler]

From the July 2026 direction review (§4.3 + §7). One small build ships a whole ecosystem cluster: GitHub Actions, Terraform modules, C/C++, Swift, Zig (and Odin) need no registry client — version-in-file (sometimes not even that) + tag + GitHub Release + a per-ecosystem post-step.

Scope

• Generic file updaters: annotation-marker style (à la release-please's x-release-please-version) + regex targets + structured JSON/TOML/YAML path targeting — "version your weird file" (Dockerfiles, docs, k8s manifests) with zero per-format code.
• Tag-only registry mode: a dispatcher target with no publish step — the tag + GitHub Release is the release; composes with existing notes/changelog/standing-PR machinery unchanged.
• Presets (thin config + docs + optional post-step each):
  • GitHub Actions: floating major-tag (v1) post-step with correct immutable-releases (GA Oct 2025) handling — dogfood on releasekit's own composite action.
  • Terraform/OpenTofu modules: per-module scoped tags (registry webhook reads them), optional README version-ref updating.
  • C/C++: CMakeLists project(... VERSION x.y.z), meson.build version:, vcpkg.json/conanfile version fields; optional GH-Release asset upload (CPack artifacts). Central-index PRs (ConanCenter/vcpkg/wrapdb) are explicitly out of scope — index-side bots own that.
  • Swift/Zig fall out free (no version file / inert version field; document only).